Sudanese government forces raided one of Darfur's largest refugee camps at dawn Monday, killing dozens of civilians, according to a witness in the camp, speaking to the AP.

Sudan's military acknowledged the raid but said soldiers were searching for smuggled weapons.

On its part, the United Nations said it was "gravely concerned" about the situation inside the Kalma camp in southern Darfur after it received reports that Sudanese police vehicles surrounded it and subsequent attacks caused "injuries and deaths of civilians."

A resident of the camp told The Associated Press that he counted 32 dead bodies, including several women and children. More than 50 vehicles "packed with armed men wearing police and security forces' uniforms ... hit us with rocket-propelled grenades and machine guns," he said.

However, a military spokesman said government troops were fired on first. "They were surprised by heavy gunfire from within the camp. There was an exchange of fire and a number of victims," said spokesman Sawarmy Khaled. According to him, the fighting had stopped by Monday night.